Subgrouping on the basis of shared innovations may be motivated by a set of phonological innovations, as we saw above. But it may equally well, as we shall see below, or in some cases even preferably so, be based on morphosyntactic changes. Parallel to our discussion of phonetic and phonological changes and their natural basis in the preceding chapters, we will begin by investigating the methodology behind the reconstruction of morphological changes. Next, we shall ask ourselves: What are &#8220;natural&#8221; morphological and syntactic changes?